Purpose:
We have evidence that L-cysteine, the substrate for biosynthesis of hydrogen sulfide (H2S) can regulate potassium (K+)-evoked glutamate release from bovine isolated retina. However, the effect of the precursor for L-cysteine, N-acetyl cysteine (NAC) on excitatory neurotransmission has not been fully elucidated. In the present study, we compared the mechanisms by which L-cysteine and NAC regulate K+-evoked [3H] D-aspartate release and glutamate-induced neurotoxicity in bovine retina.

Methods:
Isolated neural retina were incubated in oxygenated Krebs solution containing 200 nM of [3H] D-aspartate and then prepared for studies of neurotransmitter release. The MTT assay was used to assess retinal neuron survival.